Rampant growth of metropolitan areas has left many with dysfunctional planning and governance systems. Yet these places are the prime drivers of national economies and also vital to the achievement of the new Sustainable Development Goals. Metropolitan regions are becoming the "new normal", but thinking and practice has not yet caught up. In particular, there are serious capacity constraints in developing countries where most of the metropolitan growth is taking place.

The main governance approaches are: voluntary cooperation among local governments; regional authorities or special purpose districts (as bottom-up, voluntary organizations); metropolitan-level governments (either as a second-level local government, or as a regional government established by a higher-tier government); and consolidating local government through amalgamation or annexation of territory.However, the best solution for a particular region will depend on local factors; for example, the laws and regulations of the country; the division of responsibilities (functions) among government levels - andrelated fiscal and other relations with the higher-level governments; whether there is a strong tradition of local autonomy or not; and the revenue sources available to the local governments. "In defining a governance structure one needs to weigh (a) the potentials for economies of scale and service coordination efficiency and the need to address area spill-overs and disparities, versus (b) the impact on residents’ access to their government and its responsiveness and accountability."

The report says that horizontal coordination is required at the local level, but also vertical governance integration from local level to national. An informative annex provides summaries of the governance arrangements in a selection of metropolitan regions from all across the world including London, Manila, Sydney and Sao Paulo.